Hydromechanical transmission drive



May 19, 1942.

c. w BERRY HYDRO-MECHANICAL TRANSMISSION DRIVE Filed se i. 12, 1940 2 Sheets-Sheet 1 INVENTOR.

y 1942- I c. w. BERRY 2,283,486

HYDRO -MECHAN I CAL TRANSM IS S ION DRIVE Filed 12, 1940 2 Sheets-Sheet 2 Patented MaylQ, 1942 UNITED STATES PATENT orrlca 2.28am

wfiittfiiifzfljii. w Application September 12, 1940, Serial No. $56,4Q4

This invention relates to a hydro-mechanical transmission device for transmitting power from a prime mover to a load and more particularly to a power transmission unit for changing the relative speed betweenthe prime mover and the load in response to changing conditions.

Excepting in cases where the prime mover is connected directly to the load, it is usually necessary to provide a speed changing device, oftentimes referred to as a power transmission device, for changing the speed 01' the prime mover to that required by the load. In certain types of devices it is desirable to vary this speed ratioin response to changing conditions. A very good illustration of thisis engine driven motor vehicles, which motor vehicles start from a standstill, the speed of the motor vehicle gradually increasing until the top speed is attained. Mechanical transmission or gear changing devices have been used. In conventional automobiles, three standard speeds have been quite generally accepted, that'is, low gear, intermediate gear and high gear. More recently, some motor vehicles have utilized hydraulic transmission, so as to obtain the desired flexibility in the driving mechanism. In this type 01' device, a member propels a fluidto thereby transmit power to a propelled member. In this type of device the I J power is transmitted from the prime mover to the load exclusively by the use of a hydraulic coupling unit.

In the present invention, a combination of a hydraulic fluid drive and a mechanical drive is used, that is, the power is transmitted in part bya fluid drive and in part by a mechanical' drive, the fluid drive exerting influence upon the mechanical drive. This has been accomplished by incorporating into the unit adiilerential drive mechanism which may have any predetermined maximum gear ratio. This difler'ential drive may yield to the hydraulic drive under optimum driving conditions.

An object of this invention is to provide a combined hydro-mechanical transmission unit for transmitting power.

Another object of this invention is to provide a I hydro-mechanical transmission unit capable of transmitting the power. from the source to the load, whereby the speed of the load may differ from zero speed to the speed of the driving member.

Another object ofthis invention is to provide fa hydro-mechanical power transmission unit,

that may diiIer from the input speed and from the output speed.

Another object of this invention is to provide a hydro-mechanical power transmission device, wherein the eflectiveness of the mechanical transmission device increases as the diflerential or the speed ratios increases.

Another object is to provide a hydro-mechanical transmission device, wherein the efl'ectiveness of the mechanical transmission device increases as the load increases.

Another object is to provide a hydro-mechanical power transmission device, wherein power is transmitted in either direction of rotation with the same effectiveness. Another obiectoi this invention is to provid a hydro-mechanical power transmission device,

; wherein the ratio of power transmitted by the hydraulic drive with respect to the power transmitted by the mechanical drive varies as the differential in speed varies.

Another object is to provide a hydro-mechani cal power transmission device, wherein the ratio of the power transmitted by the mechanical drive increases relative to the power transmitted by the hydraulic drive with increased load.

Other objects and advantages reside in the construction or parts, the combination thereof and the mode of operation, as will become more apparent from the following description.

In the drawings, Figure 1 is a cross sectional 1 view showing the gear arrangement and the bydraulic fluid arrangement of the hydro-mechanical power transmission device, taken substantially on the line i-l of Figure 2.

Figure 2 is a cross sectional view taken sub-- Hydraulic power transmission device Referring to the drawings, the reference character 10 indicates a drive shaft that may be connected in any suitable manner to the prime mover, such as the engine 01' a motor vehicle. i The shaft II! has keyed thereto-a collar l2, provided with a flange It. This flange ll supports I a disc-like housing member l6 joined to a second housing member i8. Members liand it may wherein an intermediary unit is driven at a spe d ill be provided with peripherally disposed flange portions I60. and lBa respectively, that may be united by welding, rivets or bolts. If the parts are riveted or bolted together, a gasket is preferably inserted between the flanges Hia andlBa, so as to provide a fluid-tight joint. The housing member l8 has fixedly attached thereto a hollow boss 20 cooperating with the inner edge of housing member IE to provide a support for a bushing 22. As the shaft 10 is driven, the housing members I6 and I8 and the parts carried thereby rotate with the shaft. The housing I 6 supports a plurality of fins or fluid propelling members 24. The fins 24 are used for propelling the 'fiuid housed within the housing, as will appear more fully later.

The housing, consisting of members l6 and I8, encloses a disc-like member 30 fixedly attached to a collar 32 carried upon'a tubular sleeve 34. This tubular sleeve 34 has fixedly attached thereto a driven shaft 36 transmitting power to the load. A suitable key 38 passes through suitable apertures in the sleeve 34 and an aperture near the end of the shaft 36. The tubular sleeve 34 is journalled in the bushing or bearing'ZZ. The disc-like member 30 supports a plurality of finlike members 40. As the'drive shaft in is driven from the prime mover, whatever its source may be, it drives with it the housing including members l6 and I8 and the fins 24. The housing provides a container for a suitable drive fiuid, so that as the housing is rotated the fins 24 propel the fluid. The propelled fluid, as is well known to those skilled in the art, tends to go towards the periphery of the housing, due to centrifugal force. The fiuid, being propelled by the fins 24, exerts a rotating force upon the finlike members 40 carried by the disc-like member able connecting means, the shaft is rotated by As the clutch usumeans of the prime mover. ally engages the load connected thereto almost immediately after the clutch pedal is released. it can readily be seen that in the absence of a speed reducing mechanism'or a hydraulic fluid drive, the releasing ofthe clutch pedal would throw a sudden load upon the engine and cause the load actuated by the engine to be jerked into speed. Such an arrangement, as is well known to those skilled in the art, is objectionable.

The hydraulic fluid drive overcomes this, objection: but the hydraulic fluid drive is conduciveto a considerable slippage, especially as the load on the clutch increases. That being the case. the ideal situation would include some auxiliary device that would aid the hydraulic fiuid device in transmittingthe motion from the prime mover to the load.

Mechanical power transmission device In the device disclosed herein. a transmission ear mechanism has been used to accomplish this result. This transmission drive mechanism simulates a differential drive in somerespects.

The differential drive mechanism includes a bevr elled gear 50. keyed or otherwise fixedly attached to the shaft ID, as for example by keys 5!. This gear 50 drives a bevelled pinion 52 jou nalled pinion 55 meshes with a gear-ring member 58 fixedly attached to a cylindrical end portion 34a integral with the sleeve 34.. It can readily be seen that if the shaft 54 is restrained from rotary movement about the longitudinal axis of the shaft ID, the speed of the shaft It! then is much greater than the resultant speed of the shaft 36. If rotary movement of the shaft 54 is restrained, then by using pinions 52 and 56 that are of the same size and these rotating in unison, and-a bevelled gear 50 thatis substantially half the size. of the gear ring 58, the speed of the shaft in will be approximately twice the speed of the shaft 36. as pairs of pinions 52 and 56. The shafts 54 and the pinions 52 and 56 are mounted for rotary movement with respect to the-shaft ID. Their rotation, however, is'controlled, as will appear more fully later.

Means for correlating the function of the IL]!- draulic power transmission device with respect to the mechanical power transmission device The inner ends of the shafts 54 are fixedly attached to a tubular sleeve 60 mounted for rotation upon the shaft I0. The sleeve 60 ter- I0. a boss 10 enclosing a bushing 12 journalle'd upon the tubular sleeve portion 34. The outer'ends of the shafts 54 are fixedly mounted in retaining means 14, which may be a continuous ringhaving a plurality of apertures, one for each of the shafts 54. The tubular sleeve 60, housing mcmbers'62 and 64, and the shaft 54 may rotate about the shaft in and the tubular sleeve 34, as

the occasion may demand. That beingthe case.

the differential drive mechanism is not a positive drive, in that the housing member 62 has been provided with a plurality of radially disposed paddle-like or propeller-like members projecting into the fluid chamber, so that as the fluid propelled by the fins 24 is rotated or propelled.

this fluid tends to propel the paddle-like members 80 and thereby rotate the housing members 62 and 64 and-the parts carried thereby. The extreme outer edges of the paddle-like members 80 are attached to a ring 82, functioning to reinforce these paddle-like members 80.

upon a shaft 54 and fixedly attached to a second bevelled pinion 56 by a retaining collar 51. The

,. fin' like members 24, rotates with the shaft.

When the housing members62 and and the I parts carried thereby rotate in synchronism with the shaft ID, the pinions or gears 52 will not ro- 'tate about the longitudinal axis of the shaft 54 and therefore the pinions 52 will lock the transmission drive, so thatthe speed of rotation of the shaft 36 is the same as the speed of the shaft synchronism, motion is transmitted from the, shaft I 0 to theshaft 36 hydraulically and mechanically. as will appear more fully from the description of the mode of operation.

Mode of operation pon rotation of the shaft H), the housing, including members l6 and [8 together with the As these parts rotate, the fluid enclosed within the housing is propelled. This fluid exerts a force There are as many shafts 54 upon the fin-like members st, tending to rotate the disc 30 and with it the tubular sleeve portion 36 and the shaft 8%. However, there is considerable slippage, especially if the load is heavy.

direction. If the shaft 36 remains at a standstill I when the shaft in rotates, the gear B, meshing with the pinion 52, will cause the spider supporting the pinions 52 and 56 to rotate in a counterclockwise direction. As the spider structure rotates in a counterclockwise, direction, the propeller-like members 80 aredriven against-the direction of flow of the hydraulic fluid as it is propelled by the fin-like members 24. The fluid tends to retard the rotation of the spider structure supporting the pinions 52 and 58 in a counterclockwise direction and exerts a pull upon this spider structure, tending to rotate the spider structure in a clockwise direction. This force exerted against the propeller-like members 80 aids the hydraulic mechanism in driving the shaft 36 in a clockwise direction, as viewed in Figure 2. When the speed ratio between the shaft [0 and the shaft 36 is two to one in the device disclosed in the drawing, the spider structure will remain at a standstill; but as it remains at a standstill, the fluid propelled by the fin-like members 24 tends to rotate the spider structure in a clockwise direction, thereby reducing the speed ratio, so that it will be less than two to one. Eventually, the entire assembly tends to rotate in unison. When this condition is atta ned, the shafts i0 and 36 will rotate at the samespeed and the mechanical transmission device will rotate as a unit with the shaft "I. As soon as conditions change, either by an increased load or the motor is accelerated or decelerated, the drive shaft l0 and the driven shaft 36 will not continue to rotate at the-same speed. As soon as the speeds of these shafts are changed, the mechanical transmission device will exert a force cooperating with the hydraulic device to attain the same speed of the shafts l0 and 38.

As the usual hydraulic fluid is not very satis-' factory as a lubricant, the housing formed by members 62 and 66 is preferably filled with a suitable lubricant for the transmission device, that is, this.housing is preferably fllled with a suitable transmission grease or oil. As the housing is ol-tight, this lubricant will continue to remain in the housing for a long period of time.

This transmission device isprimarily designed for use on automobiles. trucks and other motor vehicles; but it can easily be used wherever-a variable speed ratio drive is desired. The gradual change of the ratio in speed is directly dependent upon the amount of torque required to drive the driven member and the change in speed ratio is controlled automatically within the unit itself. When the power transmission unit is used in an automobile or other motor vehicle. this unit will allow the engine to operate at all times at its peak of emciency, irrespective of the load and the speed. This will result in increased gas mileage and less strain upon the engine and the parts driven thereby. This device is intended to replace the conventional type of multiple speed transmission used in motor vehicles and to eliminate the shifting of gears.

The same transmission device may be used to transmit power in either direction of rotation. The conventional clutch is preferably associated with this device. tween the drive shaft iii and the prime mover.

Although the disclosure shown herein incorporates the gear ratio of two to one in the mechanical transmission device, any other gear ratio may be selected to meet the required conditions. This gear ratio may depend upon the load-to m pulled, the speed and other requirements of the device. The device disclosed herein has merely been shown for the purpose of 11- lustration. Any other suitable device incorporating the same principle of operation may be used.

Part of the power is transmitted by the hydraulic device. Another part is transmitted in parallel thereto by the hydro-mechanical transmission device. tend to correlate the two drives, eventually ,re-

, sulting in the driven member rotating at the same speed as the driving member, The shape of the propeller-like members and the shape of the fin-like members 26 and 80 may be altered as required by the I load. The propeller-like members 80 may be made larger, so as to be more effective or they may be made smaller, so as to exert a lesser influence. If the propeller-like members 60 are made larger, more power will be transmitted by the mechanical transmission device. If they are made smaller, the power transmitted by the mechanical transmission device will be decreased. In the event the motor vehicle is descending an incline or a grade, the hydraulic device may function as a brake.

Although the preferred mod'flcation of the'dev ce has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combinat on thereof and the mode of operation,- which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

1. A power transmission device for transmitting power from a prime mover to a load, said power transmission device including hydraulic power transmission means for transmitting power hydraulically from the prime mover directly to the load and hydro-mechanical power transmission means for transmitting power from the prime mover to the load. said hydro-mechanical power transmission means transmitting power in addition to the power transmitted by the hydraulic power transmission means, said hydromechanical transmission means including afloatng spider having fins projecting into the fluid actuated by the hydraulic po er transmission means so as to correlate the effectiveness of the hydro-mechanical transmission means with respect to the hydraulic power transmission means. 1

2. A hydro mechanical power transmission device includ'ng fluid propelling means for transmitting power to the load hydraulically, and'me-' chanical power transmitting means cooperating with the fluid propelling means for transmitting power in addition to the power transmitted hydraulically by the first mentioned means, said mechanical power transmitting means including a drive gear member and a driven gear member, a floating spider. a pair of gear pinions mounted for unison movement upon the floating The clutch may be placed bep The propeller-like members 80 spider, one of said gear pinions meshing with the drive gear member and the other meshing with the driven gear member, hollow cylindrical means interconnected to the spider, and a plurality of fluid responsive members connected to said cylindrical means, said' fluid responsive members projecting so as to be influenced by thev er, a second gear connected to the load, a floating spider assembly having a plurality of radial- ]y disposed pairs of gear members rotating in unison, one gear member of each pair meshing with the first mentioned gear and the other gear of each pair meshing with the second gear, holcluding a round housing member and a disc with the prime mover and the other member for low fluid sealing means flxedly interconnected to v a'floating spider, a pair of gear pinions mounted for unison movement upon the floating spider, one of said gear pinions meshing with the drive gear member and the other meshing with the driven gear member, and a plurality of fluid responsive members mounted upon the spider and projecting so as to be influenced by the fluid of the propelling means.

5. A power transmission device for transmitting power i'rom a prime mover to a load, said power transmission device including hydraulic transmission means permitting the prime mover to rotate at a speed difl'ering from the speed of the load, and. mechanical power transmission means cooperating with the hydraulic transmission means for transmitting power in addition to the power transmitted by said hydraulic transmission means, said mechanical transmission means including a gear driven by the prime mover, a second gear connected to the load, and a floating spider assembly having a plurality of radially disposed pairs of gear members rotating in unison, one gear member of each pair meshing with the first mentioned gear and the other gear of each pair meshing with the secondgear, said spider assembly including a housing enclosing said gears, and a plurality of fluid propelling members projecting outwardly from the housing so as to be influenced by the fluid of the hydraulic transmission means. I

6. A power transmission device for transmitting power from a prime mover to a load, said power transmission device including hydraulic transmission means permitting the prime mover to rotate at a speed difl'ering from the speed of the load, said hydraulic transmission means inrotation with the load, each of said members being provided with radially disposed fln-like propelling members for actuating a hydraulic fluid, and mechanical power transmission means cooperating with the hydraulic transmission means for transmitting power from the prime mover to the load, said mechanical transmission means including a gear driven by the prime mover, a second gear connected to the load, and a floating spider assembly having a plurality of radialiy disposed pairs of gear members rotating in unison, one gear member of each pair meshing with the flrst mentioned gear and the other gear of each pair meshing with the second gear, said spider assembly including a housing enclosing said gears and a plurality of fluid propelling members projecting outwardly from the housing so as to be influenced by the fluid of the hydraulic transmission means.

7. A power transmission device for transmitting power from a prime mover to a load, said power transmission device including hydraulic transmission means permitting the prime mover to rotate at a speed diiiering from the speed of the load, and mechanical power transmission means cooperating with the hydraulic transmission means for transmitting power, said mechanical transmission means including a gear driven by the prime mover, a second gear connected to the load, and a floating spider assembly having a plurality of radially disposed pairs of gear members rotating in unison, one gear member of each pair meshing'with the first mentioned gear and the other gear of each pair meshing with the s ,cond gear, said spider assembly including a cylindrical housing enclosing said gears, and means actuated by the hydraulic fluid projecting outwardly from said housing, said means including a plurality of propellers and a peripherally disposed ring secured to the end of the propellers rotation with the load. each of said members being provided with radially disposed fln-like propelling members for actuating a hydraulic fluid. and mechanical power transmission means cooperating with the hydraulic transmission means for transmitting power from the prime mover to the load, said mechanical transmission means including a gear driven by the prime mover, a second gear connected to the load, and a .floating spider assembly having a plurality of radially disposed pairs of gear members rotating in unison, one gear member of each pair meshing with the flrst mentioned gear and the other gear of each pair meshing with the second gear, said spider assembly including a cylindrical housing enclosing said gears, said cylindrical housing being mounted within the round housing, and fluid propelling means projecting outwardly from the fluid propelling means including a plurality of radially disposed propellers and a cylindrical ring fixedly attached to the ends of the propellers for reenforcing the same.

9. A power transmission device for transmitting power from a prime mover to a load, said power transmission device including hydraulic transmission means permitting the prime mover to rotate at aspeed differing from the speed of the .load, said hydraulic transmission means including a round housing member and a disc member mounted within the housing member, one of said members being attached for rotation with the prime mover and the other member for rotation with the load, each of said members being provided with radially disposed fin-dike propelling members for actuating a hydraulic fluid, and mechanical power transmission means cooperating with the hydraulic transmission means for transmitting power from the prime moved to the load, said mechanical transmission means including a gear driven by the prime mover, a second gear connected to the load, a floating spider assembly having a plurality of radially disposed pairs of gear members rotating in uni:- son, one gear member of each pair meshing with the first mentioned gear and the other gear member of each pair meshing with the second gear, hollow fluid sealing means fixedly interconnected to the spider, and a plurality of fluid propelling members projecting outwardly from said fluid sealing means and within the houshydro-mechanical transmission means including a gear driven by the prime mover, a second gear connected to the load, and a. floating spider assembly having a plurality of radially disposed pairs of gear members rotating in unison, one gear member of each pair meshing with the first mentioned gear and the other gear of each pair meshing with the second gear, said spider assembly includinga cylindrical housing enclosing ing member so as to be influenced by the fluid of the hydraulic transmission means.

10. A power transmission. device for transmiting power from a prime mover to a load, said power transmission device includirm hydraulic power transmission means for transmitting power hydraulically from the prime mover directly to the load and hydro-mechanical power transmission means ior transmitting power from the prime mover to the load, said hydro-mechanical power transmission means transmitting power in addition to the power transmitted by the hydraulic power transmission means, said hydro-mechanical power transmission means including a gear driven by the prime mover, a second gear connected to the load, and a floating spider assembly having a plurality of radially disposed pairs of gear members rotating in unison, one gear member of each pair meshing with the first mentioned gear and the other gear of each pair meshing with the second gear, said spider assembly including a housing enclosing said gears and a plurality of fluid propelling members projecting outwardly from the housing so as to be influenced by the fluid of the hydraulic transmission means.

said-gears, and means actuated by the hydraulic fluid projecting outwardly from said housing,

said means including a plurality of propellers and a peripherally disposed ring secured to the end of the propellers for reenforcing the same.

12. A power transmission device for transmitting power from a prime mover to a load, said power transmission device including a hydraulic power transmission'means, said means including a round housing member and a disc member mounted within the housing member, one of said members being attached for rotation with the prime mover and the other member for rotation with the load, each of said members being provided with radially disposed fin-like propelling members for actuating a hydraulic fluid, and hydro-mechanical power transmission means for transmitting power in parallel with the aforementioned hydraulic power transmission means from the prime mover to the load, said hydromechanical power transmission means including a gear driven by the prime mover, a second gear connected to the load, and a floating spider 'as- I sembly having a plurality of radially disposed pairs of gear members rotating in. unison, one gear member of each pair meshing with the first mentioned gear and the other gear of each pair meshing with the second gear, said spider assembly including a cylindrical housing enclosing said gears, said cylindrical housing being mountedwithin the round housing, and fluid propelling means projecting outwardly from the cylindrical housing, so as to be influenced by the fluid of the hydraulic transmission means, said fluid propelling means including a plurality of radially disposedpropellers and a, cylindrical ring fixedly attached to the ends of the propellers for rcenv forcing the same, I

CHARLES W. BERRY. 

